Sealing large pumps, agitators and mixers with Split Mechanical Seals

Split mechanical seals are widely accepted in almost every industry and application. The chemical industry is convinced of the benefits of this seal on large rotating equipment systems and puts to use split seals, among others for agitators, mixers and pumps


Facts for operators

1. Split mechanical seals are a reliable solution for sealing all large pumps, agitators and mixers.
2. Their biggest technical advantage is the fast turnaround of plant availability and production: users can install the seals without equipment disassembly.
3. The seals meet the requirements of the Atex and clean air policy and can be used universally.

Since their introduction in 1986 split mechanical seals are now commonly found in process industries around the world and are used to simplify maintenance tasks and reduce the associated costs. The chemical industry is convinced of the benefits of this type of seal on large rotating equipment such as agitators, mixers and pumps. Since then time has not stood still, and so manufacturers have developed since the introduction of the first generation numerous technical improvements with which the features and applications for split mechanical seals are greatly expanded: Split Seals initially found only in the simplest applications, such as industrial water pumps, today even in demanding applications in many industries as both single- as well as double-seal configurations.

Production instead of repair
The operating parameters of the present generation have been expanded to cover vacuum (711 mm Hg) up to about 35 bar (g). All split versions are ATEX certified and all double-acting versions are TA-Luft compliant. Shaft diameters available are from 25 to 300 mm. However, larger diameters are also not a problem: Seal manufacturer Chesterton for example provides split seals for water turbines up to 700 mm shaft diameter. The biggest advantage of a split seal, however, is that the conversion of the sealing point can be carried out without disassembling the equipment. Example is the 442C-seal manufacturer: One of the hallmarks of this seal is the use of split O-rings which are not glued and are at any time to re-open by the operator. Another important feature is the divided sliding surfaces reach their tightness by a special break and connection technology.

Applications: everywhere
Pressure balanced Face Geometry is a fundamental principle of the seal manufacturer, which is also used in Split Mechanical Seals to allow an even pressure distribution on the surface and thus a long service life. The ability of these split mechanical sealsto seal vacuum is made ​​possible by the shape of the seal faces and through the seat of the stationary O-ring, bringing operators the benefits in the form of a high universality of application areas. Outside springs keep the faces together, prevent rotation of the static seal ring and reduce the axial length of the seal so that it fits into tight spaces. A variety of other features enable fast and simplified installations such as the captured fasteners and fully tapped gland halves allowing the fasteners to be used in either gland half, and also the pre fitted spacers preventing the need for setting measurements.

The Author

Marcel Blagajski is Key-Account, OEM and Enduser Manager for Chesterton International GmbH